imp(ibc-client): rm TryFrom<Error = ClientError> restriction

[rnbguy]

Closes: #1203

Description

• Removes Error = ClientError in TryFrom implementations. This prevented TryFrom<Error = Infallible> from being reused.
• Reverses the direction of Convertible - so that ClientStateDecoder and ConsensusStateDecoder can be replaced by Convertible<Any>.

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PR author checklist:

• Added changelog entry, using unclog.
• Added tests.
• Linked to GitHub issue.
• Updated code comments and documentation (e.g., docs/).
• Tagged one reviewer who will be the one responsible for shepherding this PR.

Reviewer checklist:

• Reviewed Files changed in the GitHub PR explorer.
• Manually tested (in case integration/unit/mock tests are absent).

[codecov]

Codecov Report

Attention: Patch coverage is 96.55172% with 2 lines in your changes are missing coverage. Please review.

❗ No coverage uploaded for pull request base (main@ed4f8cd). Click here to learn what that means.

Files	Patch %	Lines
...nts/ics07-tendermint/src/client_state/execution.rs	83.33%	2 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1204   +/-   ##
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  Coverage        ?   64.43%           
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  Files           ?      229           
  Lines           ?    22041           
  Branches        ?        0           
=======================================
  Hits            ?    14202           
  Misses          ?     7839           
  Partials        ?        0           

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[rnbguy]

Looks like, with this - we can remove types::ClientState and types::ConsensusState usage in ICS-07 and use client_state::ClientState and consensus_state::ConsensusState directly.

This will reduce confusion for downstream users.

[seanchen1991]

Nice; this is a really cool change! 👍